T-square.



PATENTED APR. 12, 1904.

F. E. SMALL.

T-SQUARB. APPLICATION FILED JULY 10, 1903. N0 MODEL.

Tarps Patented April 12, 1904.

Warren.

FRANK E. SMALL, OF BROOKLYN, NEW YORK, ASSIGNOB OF ONE-HALF TO JAMES W. KENT, OF BROOKLYN, NEW YORK.

T-SQUARE.

SPECIFICATION forming part of Letters Patent No. 756,987, dated April 12, 1904.

Application filed July 10, 1903. Serial No. 165,007. (No model.) i

To all whmn it. may concern:

Be it known that I, FRANK E. SMALL, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of New York, have invented certain new and use ful Improvements in T-Squares, of which the following is a specification.

The invention relates to improvements in T-squares; and it consists in the novel features and combinations of parts hereinafter described, and particularly pointed out in the claims.

The invention consists in novel clamping means applied to the handle of a T-sduare whereby the T-square may be yieldingly held upon a plain drawing-board and permitted to be given its usual movements along or over said board, the clamping means of my invention being applicable to all usual T-squares and drawing-boards and being adapted in addition to holding the square upon the board to cause the edges of the handle to closely'engage the edges of the board during the movement of the square along the board.

The invention will be fully understood from the detailed description hereinafter presented, reference being had to the accompanying drawings, in which Figure 1 is a top view, partly broken away, of a drawing-board and T-square, the latter being equipped with'the clamping means constituting my invention. Fig. 2 is a bottom view of same, and Fig. 3 is a sectional view of same on the dotted line 3 3 of Fig. 1.

In the drawings,10 designates a portion of a customary form of drawing-board, 11 the usual blade of a T-square, and 12 the customary handle for said blade, the latter,as usual,being adapted to rest smoothly upon the board 10 while the inner edge of said handle is in engagement with the edge of said board 10. The

' blade 11 and handle 12 are of well'known form end the outwardly-extending arms 14, carrying rollers 15, preferably provided on their periphery with the rubber or other soft covering 16. The springs 13 are of wire, and the arms 14 press the rollers 15 in a direction against the back of the board 10, and in addition the said arms 14 may have a slight yielding movement laterally when the handle 12 is moved either upwardly or downwardly along the edge of the board 10. The springs 13 may be secured to the handle 12 by any suitable means, and in the present instance I secure the said springs by means of screws 17, extending through said handle and engaging at their lower ends plates 18, disposed within the springs 13, while at their upper ends the said screws 17 are provided with thumb-nuts 19. The springs 13 may be either permanently or detachably secured to the handle 12; but in the present instance I have shown them as being detachably secured to said handle, so that said springs may be transferred from one T-square to another, as may be desired. Upon removing the thumb nuts 19 the screws 17 may be slipped downwardly through the apertures in V the handle 12. WVhen the springs and rollers are in position upon the T-square, the latter may be applied upon the board 10, with the blade 11 at the upper side of said board and the rollers 15 pressing against the lower side thereof, and when the parts are in this condition the rollers 15 act as spring-clamps for retaining the T-square in position upon the board, and at the same time the rollers 15 permit the T-square to be moved along the board, since, as will be observed, the said rollers 15 are in position to rotate in the line of the movement of the handle 12 whether thelatter be pushed upwardly or downwardly along the edge of the board.

A further important feature of the invention is that since the arms 14 are slightlyflexible they may yield laterally to a limited eX- tent during the movement of the handle 12 and that the latter will by them be pulledinwardly against the edge of the board 10 during the movement of said handle either upwardly or downwardly along said edge, and

hence the blade of the T-square will always be in proper condition upon the board or the drawing-paper fastened thereon. If, for illustration, the handle 12 (looking at Fig. 2) should be pushed upwardly along the edge of the board 10, the resistance offered by the rollers 15 pressing against the board will result in the handle starting on its movement a little in advance of the starting of the rollers 15, and hence the retardation of the rollers 15 will cause a lateral yielding of the arms 14, the arms 14 under such condition inclining downwardly and placing the wheels 15 at a slight angle to the edge of the board 10. The movement upwardly of the handle 12 while the rollers 15 and arms 14 are in the angular position just above described causes the rollers to endeavor to travel inwardly from the edge of the board 10, this resulting in said rollers, through the arms 14, effecting a pulling action on the handle 12, drawing the latter closely against the edge of the board 10. When the handle 12 is moved downwardly, (looking at Fig. 2,) it will start slightly in advance of the rollers 15, with a result of inclining the arms 14 and said rollers, so that, as above described, the said rollers will during the downward movement of the handle 12 keep the latter pulled inwardly and closely along the edge of the board. When the T-square is moved upwardly and then downwardly, the said square during the first portion of its downward movement and during a very short duration will be slightly forced away from the edge of the board while the arms 14 are moving to their new inclination, due to such downward movement of the square. My invention therefore not only comprises a springclamp for holding the T-square upon the board and permitting said T-square to be given its usual movement, but also includes a clamping means embodying rollers and arms adapted to compel the handle 12 during its movement to automatically hug against the edge of the drawing-board. The clamp pre sented herein also permits the blade 11 to be tilted upwardly from the face of the board 10 without detaching the entire T-square from the board, this upward tilting of the blade 11 being accomplished by simply pressing downwardly upon the upper face of the handle 12.

I do not confine my invention to all of the details of construction shown in the drawings, since it is obvious that these in some respects may be varied at will.

I regard it as important that my invention may be applied to the handle of any T-square and that the T-square may be used upon all usual drawing-boards without any alteration in the construction of the latter, it not being necessary with my invention to provide any guides on the board for the rollers 15. My invention constitutes a clamp and guide and is capable of use in connection with any ordinary drawing-board or table, and it is to be observed that the said clamp not only performs the duty of connecting the square with the drawing-board, but serves to draw the blade of the square fiat against the upper surface of the board, while the rollers or runners 15 yieldingly engage the lower plain surface of said board. The rollers 15 constitute runners, which are preferably, though not in every instance necessarily, in the form of rollers.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The square comprising a blade and handle, combined with a spring-clamp applied-to said handle and extending inwardly therefrom to yieldingly engage the lower surface of a drawing-board and bind said blade against the upper surface of same; substantially as set forth. Y

2. The square comprising the blade and handle, combined with a spring-clamp applied to said handle and comprising an arm extending inwardly from said handle and carrying a runner to yieldingly engage the lower surface of adrawing-board and bind said blade against the upper surface of same; substantially as set forth.

3. The square comprising the blade and bandle, combined with a spring-clamp applied to said handle and comprising an arm extending inwardly from said handle and carrying a runner to yieldingly engage the lower surface of a drawing-board and bind said blade against the upper surface of same, said arm being adapted to yield laterally in a pivotal manner when the square is moved along the board, whereby said runner will become deflected and draw said handle against the edge of the board; substantially as set forth.

4. The square comprising the blade and handle, combined with a spring-clamp applied to said handle and comprising an arm extending inwardly from said handle and carrying a roller having a soft periphery to yieldingly engage the lower surface of a drawing-board and bind said blade against the upper surface of the same; substantially as set forth,

5. The square comprising the blade and handle, combined with a spring-clamp applied to said handle and comprising an arm extending inwardly from said handle and carrying a roller having a soft periphery to yieldingly engage the lower surface ofa drawing-board and bind said blade against the upper surface of the same, said arm being adapted to yield laterally in a pivotal manner when the square is moved along the board, whereby said roller will become deflected and draw said handle against the edge of the board; substantially as set forth.

6. The square comprising a blade and handle, combined with a clamp applied to said handle and comprising a pair of springs having inwardly-extending arms carrying run-' tiers to yieldingly engage the lower surface of No. 756,987. PATENTED APR. 12, 1904. F. E. SMALL.

T-SQUARE. APPLICATION FILED JULY 10, 1903. no MODEL.

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